Method of preventing growth of fungi



Patented Sept. 21, 1943 UNITED STATES PATENT OFFICE. I manic!) or 5.5 1322% Gaow'rn or i I No Drawing.

1939. Serial No. 298,635.

Original application October 9,

Divided and this application November 23, 1942, Serial No. 466,664

10 Claims.

The present invention relates to a. method of preventing the growth of fungi on plant material by the use of a new series of v mercuriacetylicle compounds. It will be fully understood from the following description, illustrated by specific examples of compounds which may be used in accordance with the present invention.

This application is a divislonof my copendin: application Serial No. 298,635, filed October 9, 1989.

The compounds which may be used in accordance with the present invention are anew series of mercuri-acetylide compounds which are characterized by solubility in dilute aqueous alkaline solutions or water or both, as well as various organic solvents. These compounds may be prepared by reacting a mercuri-acetylide compound of the general formula R1ORa-Hg-CECHg-R2OR1 in which R1 represents an alkyl group and R: a

hydrocarbon radical of the class consisting of the aliphatic and alicyclic groups with an organic nitrogen compound generally which has an amido 25 or imido radical containing a replaceable labile or acidic hydrogen atom, thereby replacing the Ri-O- or alkoxy group of the mercuri-acetylide compound. Organic nitrogen compounds having the characteristics above set forth which I have employed in carrying out my reaction include the amides and imides of carboxylic and sulfonic acids, and also various pyrroles and pyrrole derivatives, morpholine and the like. For example, I have used acetamlde, propionamide, urea, benzamide, salicylamide, phthalimide, succinimide, 5,5-diethylbarbituric acid, benzene sulfonamide, amino-benzene sulfonamide, paratoluene sulfonamide, morpholine,'carbazo1e, and pyrrole.

The reaction is preferably conducted in the presence of an organic solvent in which the reactants arev partially or completely soluble. It is preferred that the solvent selected has a boiling point below the melting point of the mercuriacetylide compound used in the reaction and that the reactants be completely dissolved, although these conditions are not essential. The solvent does not appear totake part in the reaction.

For example, methanol, ethanol, isopropanol,

sec.-butanol, toluol, benzol, methyl ethyl ketone,

acetone, butyl or ethyl acetates or propionates or the like may be employed as solvents.

In the resulting compounds, one valence of each mercury atom is bonded to an acetylenic 5 carbon atom and the other to a carbon atom'of a hydrocarbon. group which is apparently bonded to a nitrogen atom of an organic nitrogen compound and preferably to a nitrogen atom of an amido or imido group in the organic nitrogen compound, This structure is indicated by the fact that, when reacted upon with sodium stannite, the compounds produced yield metallic mercury very slowly as contrasted with compounds having a mercury nitrogen linkage, which, with the same reagent yield metallic mercury quickly.

The compounds which may be used in accordance with my invention have the probable gen eral formula wherein (A) is an organic nitrogen-containin group of the class consisting of substituted amido and substituted imido groups and R is a hydrocarbon radical of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the

nitrogen atom of the nitrogen-containing group being bonded to a carbon atom of the hydrocarbon radical. They are of particular value as germicides and fungicides, for example, in the treatment of wood, in cut or uncut form to prevent fungus diseases such as "blue stain" on lumber, and in the treatment of seedto disinfect and immunize' the same against infection. These compounds are substantially odorless and, for all practical purposes, are non-corrosive to iron, hence lendingthemselves for use in iron rnachinery and the like. An outstanding advantage of the compounds in accordance with my invention is the fact that they are non-vesicant and 40 do not irritate or cause blistering of the skin,

thereby enabling them to be handled without fear The following examples lllustrate methods of preparing these soluble organic mercury compounds. It is, of course, to be understood that my inventionis not to be construed as limited to the compounds therein set forth or to the methods of making them since other compounds and other methods will suggest themselves from the foregoing and from the following illustrative examples. In the examples, the term parts" indicates parts by weight.

Example 1 20 parts of bis-beta-methoxyethyl-mercuriacetylene and 13 parts of phthalimide are dissolved in about 300 parts of isopropyl alcohol. The solution is refluxed for about two hours, at

which time the reaction is completed; and the solvent is removed as by vacuum distillation. The reaction product. apparently the compound bis-beta-phthalimido-N-ethyl-mercuri-acetylene, is dried in vacuo. The compound is soluble in warm aqueous sodium carbonate and in boiling water. It sinters at 142 C. and melts completely at 166 C.

In tests conducted by me I have found that this compound will kill the sap stain" fungi,

Ceratostomella pilifera and Graphium rigidum i in a nutrient agar medium in a concentration less than 1 part per million. This reaction product is also toxic to the wood rotters, Fomes annosus and Lenzites trabea in concentrations of one-half part per million.

The compound bis-beta-phthaiimido-N-ethylmercuri-acetylene is effective as a "blue stain" 30 formula HrC-C mercury slowly on the addition of sodium stannite. It is an excellent germicide and fungicide although not quite as effective as the compound of Example 1.

By suitable control of the proportions. of the same reactants so that only one molecule of urea reacts with the alkoxyalkyl-mercuri-acetylene, a compound having the apparent formula may be produced. Simflarly, by reaction with the diamides of other dibasic acids of the dicarboxylic and disulfonic classes, other similar cyclic compounds may be produced, such as is removed as by vacuum distillation. The reaction product, which appears to have the 1 H: --CO preventative. Thus, for example, a mixture containing 5% to of this compound and 95% to 90% of sodium carbonate is dissolved in about 400 times. its weight in water to form an impregnating solution which is especially suitable forthis purpose. The wood, either green" or partially dried, is dipped into this impregnating solution and the wood is thereby protected against the action of stain and rot fungi.

This phthalimido compound is also especially suitable 'as a dry seed disinfectant. For this purpose, it is mixed with the usual inert diluents such as, for example, talc, starch, kieselguhr, chalk, clay r gypsum, with or without a wetting agent. Thus, for example, a uniform and intimate mixture of about 5 parts by weight of hisbeta-phthalimido-N-ethyl-mercuri-acetylene in about 95 parts of talc provides a highly effective immunizer against seed-borne fungus diseases when used in the-ratio of about one-half to about 2 ounces per bushel of seed.

Example 2 10 parts of bis-beta ethoxyethyl-mercuriacetylene and 3 parts of urea are dissolved in about 200 parts of sec.-butyl alcohol. The solution is refluxed for about 2 hours, at which time the reaction is complete, and the solvent is removed as by vacuum distillation, The reaction product is dried with the formation of a white crystalline material which melts at 95 C. It appears to have the formula The product is readily soluble in cold water, sodium carbonate and caustic soda solutions as well as in acetone, methanol and ethanol. The compound does not deposit mercuric oxide when treated with caustic soda-and yields metallic is dried in vacuo. The product is soluble in water, aqueous sodium carbonate, acetone, methanol and is an effective germicide and fungicide. In general, it has substantially the properties of the compound of Example 2.

If desired, the compounds bis-beta-ethoxyethyl mercuri acetylene, bis-delta-propyloxybutyl-mercuri-acetylene, bis-cyclohexyloxyethylmercuri-acetylene and the like may be reacted with succinimide as in Example 2 to obtain products similar to that obtained in accordance with this example.

Example 4 10 parts of bis-beta-methoxyethyl-mercuriacetlene and 6 parts of benzene sulfonamide are dissolved in about 200 parts of toluene. The solution is refluxed for about two hours, at which time the reaction is complete, and the solvent is removed as by vacuum distillation. The reaction product is dried with the formation of a white crystalline powder which appears to have the probable formula:

CaHs-SOr-NH-CHa-CHr-Hg-Ca The compound produced in accordance with this example has substantially the properties of the compounds produced in accordance with the preceding examples.

I claim:

1. The method of preventing and controlling the growth of fungi on plant material and of disinfecting the same which comprises applying thereto a symmetrical organic mercury compound of the general structural formula wherein (A) is an. organic nitrogen-containing radical of the class consisting of the radicals OOl]I-- and --SO:1}T-

and R is a hydrocarbon radical of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the nitrogen atom of the nitrogen-containing radical (A) being bonded to a carbon atom of the hydrocarbon radicalR.

2. The method of preventing" and controlling the growth of fungi on plant material and of disinfecting the same which comprises applying thereto an aqueous solution containing a symmetrical organic mercury .compound of the general structural formula v wherein (A) isan organic nitrogen containing radical of the class consisting of the radicals and R is a hydrocarbon rad cal of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the nitrogen atom of the nitrogen-con taining radical (A) being bonded to a carbon atom of the hydrocarbon radical R.

3. The method of treating seed to control and prevent the growth of fungi thereon and to disinfect the seed which comprises applying thereto an effective proportion of a symmetrical organic mercury compound of the general structural formula wherein (A) is an organic nitrogen-containing I radical of the class consisting of the radicals CO-1TT and SO2I;T-

and R is a'hydrocarbon radical of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the nitrogen atom of the nitrogen-containing radical (A) being bonded to a carbon atom of the hydrocarbon radical R. 4

4. The method of treating lumber to control and prevent the growth of blue stain and like fungous disease thereon which comprises applying thereto a solution of a symmetrical organic mercury compound of the general structural formula wherein (A) is an organic nitrogen-containing radical of the class consisting of the radicals and R is a hydrocarbon radical of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the nitrogen atom of the nitrogen-containing radical (A) being bonded to a carbon atom of the hydrocarbon radical R.

5 5. The method of preventing and controlling the growth of fungi on plant material and of disinfecting the same which comprises applying thereto a symmetrical organic mercury compound of the general formula wherein (A) is an organic radical containing an imido nitrogen atom and R is a hydrocarbon 1 radical of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the said nitrogen atom of radical (A) being bonded to a carbon atom of the hydrocarbon radical R.

6. The methodof preventing and controlling 2 the growth of fungi on plant material and of disinfecting the same which comprises applying thereto a symmetrical organic mercury compound of the general formula wherein (A). is an organic radical containing an imido nitrogen atom bonded to an acyl group of said organic radical and R is a hydrocarbon radi- 30 cal of the class consisting of the aliphatic and alicyclic hydrocarbon radicals, the said nitrogen atom of radical (A) being bonded to a carbon atom of the hydrocarbon radical R.

7. The method of preventing and controlling 35 the growth of fungi on plant material and of disinfecting the'same which comprises applying thereto the compound bis-beta-phthalimido-N- ethyl-mercuri-acetylene.

8. The method of preventing and controlling 40 the growth of fungi on plant material and of disinfecting the same which comprises applying thereto an alkaline aqueous solution containing the compound bis-beta-phthalimido-N-ethylr mercuri-acetylene. 9. The method of preventing and controlling the growth of fungi on plant material and of disinfecting the same which comprises applying thereto the compound having the general formula NH2CO-NHCH2-CH3-H8'CE CHg-CH2CH2-NHCONH2 C-Hg-CHz-CHr-NH-SOa-CcI-In MORRIS H. DASKAIS. e5 

